US5274350A - Shunt apparatus for current sensing and power hybrid circuits - Google Patents
Shunt apparatus for current sensing and power hybrid circuits Download PDFInfo
- Publication number
- US5274350A US5274350A US07/985,408 US98540892A US5274350A US 5274350 A US5274350 A US 5274350A US 98540892 A US98540892 A US 98540892A US 5274350 A US5274350 A US 5274350A
- Authority
- US
- United States
- Prior art keywords
- shunt resistor
- layer
- resistor according
- base layer
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
Definitions
- This invention relates generally to current sensing and more particularly to shunt resistor apparatus for use with solid state power controllers.
- each load circuit incorporates both a relay for switching current and a thermal circuit breaker to protect the circuit wiring from overloads.
- the relay and circuit breaker for many circuits are located in the cockpit for flight crew operation requiring heavy gage wire to run from the generator to the cockpit and then to the load resulting in a substantial weight penalty.
- a solid state protective circuit which is capable of remotely switching power to a load in which an electrothermal sensor is positioned in heat transfer relationship with a resistive element in series with the power line to the load to monitor the current to the load and provide a signal to control logic indicative of the sensed current determined from the amount of heating caused by the current flow through or in the line coupled to the electrothermal sensor, the amount of heat being determined by the electrothermal sensor.
- the controller in the referenced application uses a shunt resistor as a current sensing mechanism.
- the shunt resistor is adapted to conduct the full current load from the power generator to the load and the controller measures the voltage drop across the resistor apparatus and processes this measurement to limit current to the load to a safe level.
- the controller limits current in accordance with a selected curve of time versus percent overload current.
- An example of a controller of this type comprises a hybrid assembly having a substrate on which are mounted selected ASICS, FETS, resistors, capacitors and a back-up fuse as well as the shunt resistor in a package in the order of two inches in length, one and a third inches in width and a third of an inch in height.
- shunt resistor for use with the controller is the small amount of space available for the resistor and the need to conform with standard hybrid assembly techniques.
- the shunt resistor must be able to dissipate the power that the controller is designed to handle and still be able to be of a size and type to be mounted within the controller package.
- Conventional discrete resistors which have the ability to handle the required power are too large to fit within the package.
- Conventional thick film resistors are not suitable because of their limitations in power dissipation.
- Other devices which are unsuitable include plastic encapsulated wire welded to contacts. While these devices can handle the normal steady state power loads they are not able to handle the required overload and as a result overheat on such overloads and crack or even break out of their encapsulants due to wire expansion.
- Another object of the invention is the provision of a shunt resistor which is amenable to surface mount technology and which has high current carrying capability along with a stable resistance over a wide temperature range for which the controller is designed to operate, e.g. , from -565° C. to 80° C.
- Yet another object is the provision of a shunt which is reliable and cost effective.
- the circuit layer allows low resistance values to be obtained (e.g., 1 to 100 mohms) with required accuracy of +/-10% and temperature stability within +/-50 ppm/° C. -55° up to 150° C.
- the circuit layer has first and second wire bond portions on opposite ends thereof for power line attachment and first and second pad locations intermediate the ends so that wire bonds will be properly separated to yield the required resistance and therefore to sense precise voltage drop.
- FIG. 1 is a perspective view of a solid state power controller package, partly broken away to show a shunt resistor made in accordance with the invention
- FIG. 2 is an enlarged perspective view of the shunt resistor shown in FIG. 1;
- FIG. 3 is a graph of trip time versus percent overload current of a controller with which the shunt resistor is used.
- FIG. 4 is a graph of resistance versus temperature of a shunt resistor made in accordance with the invention conducting various load currents.
- a solid state power controller 10 comprising a package 12 containing a substrate 14 on which is disposed circuit traces as well as various hybrid components (not shown) including resistors, capacitors, FETS and ASICS.
- a shunt resistor 20 is disposed in package 12 and is surface mounted to substrate 14 by conventional hybrid surface assembly techniques, such as by being fixed thereto with suitable epoxy.
- shunt resistor 20 comprises a base layer 22 selected to facilitate heat removal, provide mechanical strength and to be compatible with conventional hybrid substrate mounting techniques.
- a circuit layer 24 is disposed on base layer 22 with a dielectric layer 26 therebetween.
- Layer 24 is formed of a metal foil of material selected having the desired resistivity and a low thermal coefficient of resistance (tar)-plus or minus 50 ppm/° C. resistance change over the operating temperature range and up to 150° C., and to be compatible with wire bonding techniques.
- Dielectric layer 26 is formed of a material which not only provides the required electrical isolation between circuit layer 24 and base layer 22 but also is thermally conductive in order to dissipate the energy generated in the circuit layer and therefore must be capable of forming a good physical bond between layers 22, 24.
- Circuit layer 24 is preferably formed of Monel 401 (55% Cu-45% Ni alloy) since it meets all of the above noted requirements.
- Monel 401 is wire bondable and is cost effectively formed into its desired resistance pattern by conventional etching techniques. The material can also be effectively bonded to the base layer using thermally conductive material to be explained below. Monel 401 also has a low temperature coefficient of resistivity within the required operating temperature range.
- Base layer 22 is preferably formed of aluminum which meets the requirements of thermal conductivity, mechanical strength, conformance with conventional hybrid mounting techniques and being readily bondable to the selected dielectric layer 26.
- Dielectric layer 26 is preferably formed of a ceramic filled polymer having a thermal conductance of approximately 3 watts/meter K or greater in order to provide effective thermal transfer while minimizing size.
- the shunt is constructed by taking an aluminum base layer 22 of convenient thickness, e.g., 014.067-0.057 inch, and a monel foil for circuit layer 24 of a selected thickness and placing dielectric layer 26 of a selected thickness therebetween and pressing the assembly together under suitable temperature and pressure conditions to adhere layer 26 to both layers 22 and 24.
- Ceramic filled polymer material of this type is disclosed in U.S. Pat. Nos. 4,810,563 and 4,574,879 and is available from The Bergquist Company.
- circuit layer 24 is formed with wire bond areas 28, 30 at opposite ends thereof to permit bonding of wires 32, 34, for power in and power out respectively.
- Notches 35 and 36 serve as locators for wire bond sense pads for attachment of wires 37, 38 respectively to provide a resistance C which is used to monitoring voltage drop as current flow changes.
- Specific dimensions, in inches, of shunts made in several ampere ratings for both 270 VDC and 28 VDC are shown in the table below in conjunction with FIG. 2.
- the thickness of the dielectric layer 26 (E) was 0.0029-0.0025 and the thickness of circuit layer 24 (F) was 0.0037-0.0033 in each of the above examples.
- the E and F dimensions were selected based on the need to provide power dissipation as well as the practicality and cost effectiveness related to etching times. It will be understood that using different E and F dimensions would necessitate appropriate changes in the other dimensions to obtain the selected resistance level.
- FIG. 3 which shows maximum and minimum trip curves 40, 42 of the controller at operating temperatures of -55° C., 25° C. and 80° C. using a shunt made in accordance with the invention and having dimensions shown in the above table indicate the close grouping of the different test points due to the low TAR.
- a generally rectangular pattern has been employed with each of the ratings since it provides a desirable large surface area thereby enhancing thermal dissipation of the power it will be understood that other patterns could be used if desired.
- FIG. 4 shows resistance variations over temperature for a shunt used without the referenced controller, conducting various full load currents. It will be noted that curve 44 is within a narrow band required for precision current sensing applications.
Abstract
Description
______________________________________ AMP Rating Voltage A B C D ______________________________________ 10.0 270 VDC .120-.124 .164-.174 .198-.202 .335-.345 7.5 270 VDC .096-.100 .164-.174 .198-.202 .335-.345 5.0 270 VDC .060-.064 .164-.174 .198-.202 .335-.345 2.5 270 VDC .029-.033 .164-.174 .198-.202 .335-.345 10.0 28 VDC .218-.222 .264-.274 .408-.412 .540-.550 7.5 28 VDC .169-.173 .264-.274 .408-.412 .540-.550 5.0 28 VDC .112-.116 .264-.274 .408-.412 .540-.550 2.5 28 VDC .055-.059 .264-.274 .408-.412 .540-.550 ______________________________________
Claims (11)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/985,408 US5274350A (en) | 1992-12-04 | 1992-12-04 | Shunt apparatus for current sensing and power hybrid circuits |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/985,408 US5274350A (en) | 1992-12-04 | 1992-12-04 | Shunt apparatus for current sensing and power hybrid circuits |
Publications (1)
Publication Number | Publication Date |
---|---|
US5274350A true US5274350A (en) | 1993-12-28 |
Family
ID=25531462
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/985,408 Expired - Lifetime US5274350A (en) | 1992-12-04 | 1992-12-04 | Shunt apparatus for current sensing and power hybrid circuits |
Country Status (1)
Country | Link |
---|---|
US (1) | US5274350A (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997022130A1 (en) * | 1995-12-11 | 1997-06-19 | Caddock Electronics, Inc. | Power resistor combinations and method |
US20030090241A1 (en) * | 2001-08-22 | 2003-05-15 | Hitachi, Ltd. | Power converter with shunt resistor |
US20110026264A1 (en) * | 2009-07-29 | 2011-02-03 | Reed William G | Electrically isolated heat sink for solid-state light |
DE102012209182A1 (en) | 2011-06-06 | 2012-12-06 | Lear Corporation | Isolated resistive current sensor |
US8926138B2 (en) | 2008-05-13 | 2015-01-06 | Express Imaging Systems, Llc | Gas-discharge lamp replacement |
US8926139B2 (en) | 2009-05-01 | 2015-01-06 | Express Imaging Systems, Llc | Gas-discharge lamp replacement with passive cooling |
US9241401B2 (en) | 2010-06-22 | 2016-01-19 | Express Imaging Systems, Llc | Solid state lighting device and method employing heat exchanger thermally coupled circuit board |
US9445485B2 (en) | 2014-10-24 | 2016-09-13 | Express Imaging Systems, Llc | Detection and correction of faulty photo controls in outdoor luminaires |
US9572230B2 (en) | 2014-09-30 | 2017-02-14 | Express Imaging Systems, Llc | Centralized control of area lighting hours of illumination |
US10164374B1 (en) | 2017-10-31 | 2018-12-25 | Express Imaging Systems, Llc | Receptacle sockets for twist-lock connectors |
US11375599B2 (en) | 2017-04-03 | 2022-06-28 | Express Imaging Systems, Llc | Systems and methods for outdoor luminaire wireless control |
US11653436B2 (en) | 2017-04-03 | 2023-05-16 | Express Imaging Systems, Llc | Systems and methods for outdoor luminaire wireless control |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5057811A (en) * | 1988-12-22 | 1991-10-15 | Texas Instruments Incorporated | Electrothermal sensor |
US5128616A (en) * | 1991-02-07 | 1992-07-07 | Duracell Inc. | DC voltage tester having parallel connected resistive elements in thermal contact with a thermochronic material |
US5189593A (en) * | 1991-11-04 | 1993-02-23 | Motorola, Inc. | Integrated distributed resistive-capacitive network |
-
1992
- 1992-12-04 US US07/985,408 patent/US5274350A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5057811A (en) * | 1988-12-22 | 1991-10-15 | Texas Instruments Incorporated | Electrothermal sensor |
US5128616A (en) * | 1991-02-07 | 1992-07-07 | Duracell Inc. | DC voltage tester having parallel connected resistive elements in thermal contact with a thermochronic material |
US5189593A (en) * | 1991-11-04 | 1993-02-23 | Motorola, Inc. | Integrated distributed resistive-capacitive network |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1997022130A1 (en) * | 1995-12-11 | 1997-06-19 | Caddock Electronics, Inc. | Power resistor combinations and method |
US20030090241A1 (en) * | 2001-08-22 | 2003-05-15 | Hitachi, Ltd. | Power converter with shunt resistor |
US6794854B2 (en) | 2001-08-22 | 2004-09-21 | Hitachi, Ltd. | Vehicle power converted with shunt resistor having plate-shape resistive member |
US6960980B2 (en) * | 2001-08-22 | 2005-11-01 | Hitachi, Ltd. | Power converter with shunt resistor |
US8926138B2 (en) | 2008-05-13 | 2015-01-06 | Express Imaging Systems, Llc | Gas-discharge lamp replacement |
US8926139B2 (en) | 2009-05-01 | 2015-01-06 | Express Imaging Systems, Llc | Gas-discharge lamp replacement with passive cooling |
US20110026264A1 (en) * | 2009-07-29 | 2011-02-03 | Reed William G | Electrically isolated heat sink for solid-state light |
US9241401B2 (en) | 2010-06-22 | 2016-01-19 | Express Imaging Systems, Llc | Solid state lighting device and method employing heat exchanger thermally coupled circuit board |
US8836525B2 (en) | 2011-06-06 | 2014-09-16 | Lear Corporation | Isolated resistive current sensor |
DE102012209182A1 (en) | 2011-06-06 | 2012-12-06 | Lear Corporation | Isolated resistive current sensor |
US9572230B2 (en) | 2014-09-30 | 2017-02-14 | Express Imaging Systems, Llc | Centralized control of area lighting hours of illumination |
US9445485B2 (en) | 2014-10-24 | 2016-09-13 | Express Imaging Systems, Llc | Detection and correction of faulty photo controls in outdoor luminaires |
US11375599B2 (en) | 2017-04-03 | 2022-06-28 | Express Imaging Systems, Llc | Systems and methods for outdoor luminaire wireless control |
US11653436B2 (en) | 2017-04-03 | 2023-05-16 | Express Imaging Systems, Llc | Systems and methods for outdoor luminaire wireless control |
US10164374B1 (en) | 2017-10-31 | 2018-12-25 | Express Imaging Systems, Llc | Receptacle sockets for twist-lock connectors |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5274350A (en) | Shunt apparatus for current sensing and power hybrid circuits | |
US4866560A (en) | Safeguarding electrical transient surge protection | |
US7436284B2 (en) | Low resistance polymer matrix fuse apparatus and method | |
JP2649491B2 (en) | SMD structure resistor, method of manufacturing the same, and printed circuit board to which the resistor is attached | |
USRE39660E1 (en) | Surface mounted four terminal resistor | |
US5057811A (en) | Electrothermal sensor | |
US5038132A (en) | Dual function circuit board, a resistor element therefor, and a circuit embodying the element | |
EP1206781A2 (en) | Improvements to circuit protection devices | |
WO2009145133A1 (en) | Resistor | |
JP2002057009A (en) | Resistor and method of manufacturing the same | |
US6392528B1 (en) | Circuit protection devices | |
EP1243005B1 (en) | Monolithic heat sinking resistor | |
US6667461B1 (en) | Multiple load protection and control device | |
JP2007093453A (en) | Surface-mounted temperature sensor | |
US6121766A (en) | Current sensor assemblies | |
JP3758331B2 (en) | Shunt resistor element for semiconductor device, mounting method thereof, and semiconductor device | |
US5469131A (en) | Hybrid integrated circuit device | |
JP3552539B2 (en) | Thermal fuse with resistance | |
US6873028B2 (en) | Surge current chip resistor | |
JP2002184601A (en) | Resistor unit | |
JP2002050501A (en) | Mounting body and using method thereof | |
US4157522A (en) | Electrical melting fuse combined with a Peltier element | |
JPH04344120A (en) | Overheat protecting device | |
JP2502851Y2 (en) | Semiconductor device | |
GB2136206A (en) | Fused ceramic capacitor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: TEXAS INSTRUMENTS INCORPORATED, MASSACHUSETTS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:LARSON, ERIC K.;REEL/FRAME:006352/0351 Effective date: 19921204 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |
|
AS | Assignment |
Owner name: MORGAN STANLEY & CO. INCORPORATED, NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNORS:SENSATA TECHNOLOGIES, INC.;SENSATA TECHNOLOGIES FINANCE COMPANY, LLC;REEL/FRAME:017575/0533 Effective date: 20060427 |
|
AS | Assignment |
Owner name: SENSATA TECHNOLOGIES, INC., MASSACHUSETTS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:TEXAS INSTRUMENTS INCORPORATED;REEL/FRAME:017870/0147 Effective date: 20060427 |
|
AS | Assignment |
Owner name: SENSATA TECHNOLOGIES MASSACHUSETTS, INC., MASSACHU Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SENSATA TECHNOLOGIES, INC.;REEL/FRAME:021018/0690 Effective date: 20080430 |
|
AS | Assignment |
Owner name: MORGAN STANLEY & CO. INCORPORATED, NEW YORK Free format text: SECURITY AGREEMENT;ASSIGNOR:SENSATA TECHNOLOGIES MASSACHUSETTS, INC.;REEL/FRAME:021450/0563 Effective date: 20080430 |
|
AS | Assignment |
Owner name: SENSATA TECHNOLOGIES MASSACHUSETTS, INC., MASSACHU Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:MORGAN STANLEY & CO. INCORPORATED;REEL/FRAME:026293/0352 Effective date: 20110512 Owner name: SENSATA TECHNOLOGIES, INC., MASSACHUSETTS Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:MORGAN STANLEY & CO. INCORPORATED;REEL/FRAME:026293/0352 Effective date: 20110512 Owner name: SENSATA TECHNOLOGIES FINANCE COMPANY, LLC, MASSACH Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:MORGAN STANLEY & CO. INCORPORATED;REEL/FRAME:026293/0352 Effective date: 20110512 |